Interval timer switch



May 6, 1952 M. ZUCKERMAN 2,595,624

INTERVAL TIMER swI'rcH Filed April 29, 1949 FIG. 2.

INVENTOR. TON ZUCPXERMAN ATTO/P/VEX Eatented May 6, 1952 INTERVAL TIMER SWITCH Milton Zuckerman, Brooklyn, N. Y., assignor to Timer Research Corp., New York, N. Y.

Application April 29, 1949, Serial No. 90,300

4 Claims.

This invention relates to interval timers. More particularly, the invention is concerned with an apparatus for timing an interval and associated means for signaling the termination of the time interval, and/or deenergizing an electrical switch.

The present invention provides an interval timer which may be utilized singularly as an independent unit for timing a predetermined interval, the termination of said interval being announced by a bell or gong. In another aspect, the present invention may be utilized as a control element for non-automatic electrical devices, thus converting such devices to automatic operation. This type of timer has many applications in the fields of automatic time controlled games, X-ray machines, cooking ranges, toasters, electrical heaters and the like.

The invention utilizes the warping action of a heated bi-metallic element and its ability to return to its origina1 state upon cooling. A portion of the time interval of the timer unit is determined by the period during which the bi-metallic element is heated by means of an electrical current heater, and the remainder of the time interval is determined by the period required for the lei-metallic element to return to a predetermined condition.

It is an object of the invention to provid an interval timer of simple and inexpensive construction.

It is a further object of the invention to provide an interval timer which may be utilized to convert non-automatic electrical devices to automatic operation.

It is a further object of the invention to provide a novel interval timer, including aural signal means for heralding the termination of the time interval, and electrical switch means for controlling an external electrical circuit.

Further objects, advantages and uses of the invention will be afforded by the following detailed description considered in connection with the accompanying drawing, and those features of the invention which are believed to be novel and patentable will be pointed out in the claims appended hereto.

The invention will be described with reference to the accompanying drawings, in which:

Figure 1 is a plan view of the invention with part of a bell housing broken to expose the mechanism;

Figure 2 is a partial view showing the detent mechanism, starter switch, and contacts prior to commencement of operation of the invention;

Figure 3 is a view in elevation taken along line 2--2 of Figure 1;

Figure 4 is a partial view similar to Figure 2, showing the detent mechanism, starter switch, and contacts at the moment of commencement of operation of the invention;

Figure 5 is an electrical circuit diagram of the electrical components of the invention.

Referring to the drawings, a bi-metallic element In is secured, at one of its longitudinal extremities, to a base plate I l by means of a bracket 2. The bi-metallic element is formed with a first detent member i3, and a second detent member Hi. The first and second detent members are reversely positioned respective one another, and the first detent member is displaced from the second detent member in such manner as to permit the second detent member to become operative as the first detent member becomes inoperative. Bi-metallic element In is further formed with a heating element 15, which may be wound about the bi-metallic element, The heating element 15 provides a source of heat for warping the lei-metallic element II].

A plurality of L shaped resilient contact arms l6, I1, and i8, and a generally L shaped resilient clapper support arm [9 are spaced from one another and mounted in an insulated block 30 which is secured to bracket H2. The contact arms ll, [6 and 18 are provided with a first, second and third electrical contact point 20, 2| and 22 respectively. The contact points are arranged to permit all three to be simultaneously in electrical connection, and are spaced to permit electrical contact points 20 and 22 to remain in electrical contact although contact points 20 and 2| are not in contact.

Contact arm I8 is formed with a shoulder portion 18a, positioned for engagement with first and second detent members l3 and [4 under desirable operating conditions as will hereinafter be set forth. A starter lever 23, formed with a tooth 23a, is mounted on base plate H so that depression of the starter lever will cause tooth 23a to engage contact arm l8 and move said contact arm into position for retention by first detent member l3.

A clapper 24 for energizing a bell 25, which is supported by bracket [2, is secured to support arm l9, and placed adjacent switch contact arm The electrical circuit and operation of the timer will now be described:

To start operation of the timer, starter lever 23 is depressed from its normal position, Figure 2, wherein the contact points are shown disengaged, or out of contact. Depression of starter lever 23, moves contact arm it into a position of retention by first detent member l3, causing first contact point 20 to simultaneously form a closed contact with contact points 20 and 22.

Now referring to the electrical circuit diagram of Figure 5, both switches I and 2 are closed. An'

electrical potential applied at points A and B would cause a current to flow through heating element 15, and would further provide a source of electrical potential at points C and D through closed switch 2.

As an electrical current passes through heating element 15, the bi-metallic element is caused to warp. As the bi-metallic element is warped, first detent member I3 is moved from a position of retention of arm I8, causing arm 8 to fall to the level of second detent member i i. In this position contact between contact points 223 and 21 is broken, contact between contact points 20 and 22 remaining intact. In this position, switch I has been opened, discontinuing the flow of current through heating element 15. As the source of heat is removed, bi-metallic element iii begins to cool. Switch 2 remains closed, retaining a supply of electrical potential points C and D.

As bi-metallic element I0 cools, it slowly returns to its original position, causing second detent member It to move out of retentive engagement with contact arm i8 opening switch 2. As contact arm i8 is released by second detent member, the resiliency of arm 28 causes the arm to swing downward, strike the clapper 2 3, and drive the clapper 2s against the bell 25.

Having thus completed one cycle of operation, the interval timer may again be placed in use, and the procedure previously referred to repeated.

Having thus disclosed and described my invention, I desire to point out that modifications of the particular arrangement which I have disclosed as embodying m invention will occur to those skilled the art, so that I do not desire my invention to be limited to the particular arrangement set forth, and I intend in the appended claims to cover all modifications thereof which do not depart from the spirit and scope of my invention.

What is claimed is:

1. In an interval timer, a substantially U shaped bi-metallic element, an electrical heating element for heating said bi-metallic el ment and causing said bi-metallic element to warp, said electrical heating element being in electrical circuit with a first switch for opening and closing said electrical circuit, and a second switch, said first switch comprising a first contactor and a second contactor, said second switch comprising said second contactor and a third contactor, a first detent member and a second detent member secured to an end of said bi-metallic element, said detent members being reversely positioned and displaced one respective the other, means for manually placing said first, second and third contactors in closed circuit retention by said first detent member, said bi-metallic element upon being warped by said heating element, moving said first detent member to disengage said first, second and third contactors, said first and second contactors becoming open circuit, said second and third contactors becoming positioned in closed circuit retention by said second detent member until said bi-metallic element has cooled to a predetermined position causing said second detent member to disengage from said second and third contactors,

2. In an interval timer, a substantially U shaped bi-metallic element, an electrical heating element for heating said bi-metallic element and causing said bi-metallic element to warp, said electrical heating element being in electrical circuit with a first switch for opening and closing said electrical circuit, and a second switch. said first switch comprising a first contactor and a second contactor, said second switch comprising said second contactor and a third contactor, a first detent member and a second detent member secured to an end of said bi-metallic element, said detent members being reversely positioned and displaced one respective to the other, and a signal element, means for manually placing said first, second and third contactors in closed circuit retention by said first detent member, said bi-metallic element upon being warped by said heating element, moving said first detent member to disengage said first, second and third contactors, said first and second contactors becoming open circuit, said second and third contactors becoming positioned in closed circuit retention by said second detent member until said bi-metallic element has cooled to a predetermined position, causing said second detent member to disengage from said second and third contactors, said third contactor striking said signal member.

3. In an interval timer, a base plate, a substantially U shaped bi-metallic element secured at one of its extremities to said base plate, an electrical heating element for heating said bimetallic element and causing said bi-metallic element to warp, proximate said bi-metallic element, said electrical heating element being in electrical circuit with a first switch for opening and closing said electrical circuit, and a second switch, an insulated block secured to said base plate, said first switch including a resilient first contact arm secured to said insulated block, a first contactor secured to said contact arm, and a resilient second contact arm secured to said insulating block, a second contactor secured to said contact arm, said second switch including said second contactor, and a resilient third contact arm secured to said insulating block, a third contactor secured to said contact arm, a first detent member and a second detent member secured to said bi-metallic element at the free extremity thereof, said first and second detent members being reversely positioned and displaced one above the other, means for placing said first, second and third contact arms in retention by said first detent member, said first, second and third contactors thus being in closed circuit retention, said bi-metallic element upon being warped by said heating element, moving said first detent member to disengage said first, second and third contact arms, opening said first and second contactors, said second and third contact arms becoming positioned in closed circuit retention by said second detent member until said bi-metallic element has cooled to a predetermined position, causing said second detent member to disengage from said second and third contactors, opening said second switch.

, 4. In an interval timer, a base plate, a substantially U shaped bi-metallic element secured at one of its extremities to said base plate, an electrical heating element for heating said bi-metallic element and causing said bi-metallic element to warp, proximate said bi-metallic element, said electrical heating element being in electrical circuit with a first switch for opening and closing said electrical circuit, and a second switch, an insulated block secured to said base plate, said first switch including a resilient first contact arm secured to said insulated block, a first contactor secured to said contact arm, and a resilient second contact arm secured to said insulated block, said second contact arm including a contactor secured thereto, said second switch including a third resilient contact arm secured to said insulated block and a contactor secured to said arm, said contactor and the contactor associated with the resilient contact arm forming said second switch, and a fourth resilient arm including a signal actuating member, said fourth resilient arm being secured to said insulated block, a first detent member and a second detent member secured to said bi-metallic element at the free extremity thereof, said first and second detent members being reversely positioned and displaced one above the other, means for placing said first, second and third contact arms in retention by said first detent member, said first, second and third contactors thus being in closed circuit retention, said bimetallic element upon being warped by said heating element, moving said first detent member to disengage said first, second and third contact arms, opening said first and second contactors, said second andthirdcontactarmsbecomingpositioned in closed circuit retention by said second detent member until said bi-metallic element has cooled to a predetermined position, causing said detent member to disengage from said second and third contactors, opening said second switch, and said third contact arm striking said signal actuating member.

MILTON ZUCKERMAN.

CITED are of record in the REFERENCES UNITED STATES PATENTS Number Name Date 1,795,013 Denman Mar. 3, 1931 2,180,282 Geier Nov. 14, 1939 2,221,863 Crane Nov. 19, 1940 2,250,997 Miller July 29, 1941 2,436,735 Walder et a1. Feb. 24, 1948 2,517,697 Molmans Aug. 8, 1950 2,537,408 Hansen Jan. 9, 1951 FOREIGN PATENTS Number Country Date 259,442 Germany Mar. 7, 1913 

